The present invention relates to a self-contained, disposable diagnostic assay device, or kit, that is particu1arly useful in field locations, that is, locations distant from formal detection, or analytical, facilities. The present test kit is eminently useful in the concentration and the subsequent detection of antigens using appropriate antibody reactant systems and colorimetric reagents. The present invention is particuarly suited to use in the areas of human and veterinary medicine, biologic testing of water, and industrial effluent testing.
Although the present kit is particularly suited to use under the supervision of a person having knowledge and experience in the analytical field, it has equally wide application in the area of tests conducted by laymen and is particularly useful in the area of self-administered, or private, tests. In the latter cases, the reagents, or reactants, utilized in the kit are suitably selected to be safe under such conditions of use.
The present kit is particularly useful in the concentration and detection of selected antigens from biologic extracts by exposure of the extract to selected reactants, or reagents, typically antigens or antibodies, and subsequently identifying the presence of specific antigens by colorimetric means. Antibodies are frequently produced as a defense reaction when foreign substances are taken in, parenterally, by living bodies. Substances which produce antibodies are known as antigens. Typically, antigens are mixtures of proteins, protein degradation products, lipoids and polysaccharides, and include, for example, bacteria, viruses, blood corpuscles and toxins. The antibodies formed bind to the antigens by a highly specific reaction. Because of such high degree of specificity, antibodies can be utilized to identify the corresponding antigens. lf the presence of certain antibodies can be demonstrated in the biologic extract from an organism, it can be concluded with a high degree of certainty that the organism has at some time been exposed to the corresponding antigen. While the methods of detecting antibodies vary, they commonly comprise the step of bringing a biologic fluid, for example blood, into contact with a selected antigen. If an antigen-antibody reaction takes place, this is evidence for the presence of the corresponding antibody. It is also evidence that there has been an exposure to antigens when the corresponding antibodies are present in the sample even if the antigens are no longer present in the sample.
Various analytic or testing devices, some of which rely on antigen/antibody reactions, have been previously proposed for testing biological extracts. The most pertinent prior art relevant to the present invention presently known to applicant is as follows. U.S. Pat. No. 3,981,981 teaches a reaction vessel utilized to detect specific antigens. U.S. Pat. No. 4,081,077 discloses a compartmented package having a peelable cover and a mixing chamber. U.S. Pat. No. 4,582,685 relates to a portable test kit for performing medical tests in the field using a chemical test pad. U.S. Pat. No. Re. 29,725 teaches a multi-compartmented biomedical testing container for field use. U.S. Pat. No. 4,162,003 discloses a disposable serological test kit which may include a spot plate. U.S. Pat. No. 3,582,283 relates to a disposable test kit having a plurality of reagent storage chambers connecting to a reaction body chamber which is useful for testing fluids. U.S. Pat. No. 3,554,705 teaches a similar disposable test kit in which the reaction chamber is also useful as a cuvette for optical analysis. U.S. Pat. No. 3,835,834 relates to a disposable culture transporting device containing a culture medium. U.S. Pat. No. 3,986,834 teaches a kit for testing biological fluids wherein a standard test is conducted simultaneously with a probative test.